Automatic latch mechanism for portable extension masts



Aug. 28, 1951 H Filed Nov. 10, 1947 J. MOON AUTOMATIC LATCH MECHANISMFOR PORTABLE EXTENSION MASTS 3 Sheets-Sheet 1 James INVENTOR.

M on '%KZZW HTToR/wsy.

Aug. 28, 1951 J. MOON AUTOMATIC LATCH MECHANISM FOR PORTABLE EXTENSIONMASTS 5 Sheets-Sheet 2 Filed Nov. 10, 1947 IN vE NTOR.

ATTORNEY.

Aug. 28, 1951 J. MOON AUTOMATIC LATCH MECHANISM FOR PORTABLE EXTENSIONMASTS Filed Nov. 10, 1947 5 Sheets-Sheet 5 IN VENTO/P.

Jam 2.5 JET on ATTORNEY-1 Patented Aug. 28, 1951 AUTOMATIC LATCHPORTABLE EXTENSION MAS-TS- James Moon, Altadena, C

ern Oil Tool & Engineering Co. Inc., Hollydale, Calif., a corporation ofCalifornia Application November 10, 1947;.Serial No. 785,165

6 Claims. 1 This invention relates to a latching mechanism andparticularly to a latching mechanism forv telescoping masts, and moreparticularly this invention is designed for use as a latching mechanismin the telescoping drilling mast type of derrick employed with portableoil well drilling and servicing rigs.

Portable drilling and servicing rigs are commonly employed in thepetroleum production for the drilling and servicing of wells. Such rigsare usually transported on trucks or trailers which carry a mast orderrick which may be positioned on the truck and erected at the drillingsite. Thesemasts are usually composed of one or more sections, usuallytwo, in such form that the upper section may be telescoped into thelower section when the derrick is to be transported, and

upon erection of the lower section the telescoped derrick may bewithdrawn or extended from the lower section to give a mast ofthedesired height. This type of mast for such purposes is nowconventional and is described inPatent No. 2.204.713

and in m co-pendingapplications Serial Nos. 786,461, filed November 27,1947- and 10,412 filed February 24, 1949-.

Since such masts are called upon to carry tre-- mendous loads on theorder of 200,000 pounds, it is important that when the derrick isextended the extensible portion be securely latched in position in thelower portion.

In such derricks of the prior art, manually operable latches have beenprovided and a numberof bad accidents have occurred because of thefailure to securely latch the derrick in positionprior to application ofload- Additionally, the latches, heretofore used, may be accidentallydamaged due to improper setting when the derrick is retracted, and uponextensionof the derrick the damagedlatch fails toset and failureresults. Accidents due to this cause have also been known.

It is an object and feature of my inventionto provide a latchingmechanism which automatically latches thev extensible section of themast to the lowermost section when the extensible mast section hasreached a predetermined posi-' tion in relation to the lower sectionduring the extension thereof and will hold the upper section securely inposition under all loads designed to be taken by the derrick, and willalso automatically unlatch and move into an inoperative position whenthe derrick is tobe retracted and remain in that position during theretraction thereof.

It is a particular feature of this inventionthat the latching mechanismoperates automatically MECHANISM' FOR alif., assignor to Westandwithout-attention so thatreliance is not had uponthe human element inlatching the. derrick inpositionor unlatching it for retractionsecurelylatch. the derrick/in position.

Thelatching mechanism is at all. times out of the way, both when inoperative position and in inoperative position.

These. andother objects. of my invention. will be clear from thefollowing description taken together withthe accompanying drawings, inwhich:v

Fig. 1 isaverti'cal elevation partly fragmentary and partly schematic,showing a mastin erected position;

Fig. 2 Ba fragmentary, detail of. one of the legs.

of the extensible section showing the relationship between the legsandthe valve actuating mechanism in one position;

Fig. 2ais similar to Fig. 2 but showing the valve actuating mechanism inanother position;

Fig. 3 isa schematic showing ofv part of the piping. employed inthepneumatic actuation of the latching. mechanism; 1

Fig. 4 is a fragmentary part section takenon the line 4-4. of Fig.1.;said v section also being takenon the line. 4--4-o Fig. 5-;

Fig. 5'is afragmentarypart section taken along, the line 5-5 of. Fig. 4;

Fig- 6 is a sectiontaken. along the line 6-43 of Fig. 7, showing indiagrammatic form the piping layout and the valve mechanism in positionto movethe latches into. their operative position;

Fig. '7 is a section taken along line '|--1 of Fig 6;

Fig. Sis a. section. takenalong line 8-8 of Fig.

5; and. a

Fig. 9 is a schematic view of the valve showing it. in positionformoving the derrick to the inoperative position.

Derrick I may be mounted upon truck. 2 in any conventional. manner,such. as shown in Patent No. 2,204,713 or in my co-pending appli-r in amanner not shown, Such conbe extended from section 1 to anfelevatedposi- Lower section 'I is seppanel sections by horition as shown inFig. 1. arated into a number of zontal box girders 9a to the lowermostgirder of the lower section. These 91, inclusive; 9a forms the topgirder of the lower section, and 9 forms Another port, shown at BI (seeFigs. 3 and 6) is girders connect the front legs I2 and I3 andthe rearlegs I!) and II of the lower section, as shown;

in Figs. 4, 6, and '7.

Mounted on the front end of each of the boxgirders adjacent the frontlegs- I2 and I3 are uide channels I4 which extend between each of theadjacent box girders 9a to 9f, inclusive. These are connected to the boxgirders in the connected to the conduit 29' which is in turn connectedto two manifolded pressure lines 3| and 3|. Another port 60 is connectedto the line 29 and to the manifolded lines 32 and 32', and a fourth portis connected to the atmospheric vent 53. The bores 24a and '24h of thevalve 24 can make the connections shown in both Figs. 6 and 9, and aquarter turn will change the port position from one form to the other.

One of the box girders, preferably 9b, has its lower plate 62" cut outto form an entry to the hollow chamber 59 inside the box girder betweenthe legs I and I3 and also between II and I2. The upper plate 6I, of thebox girder is bored with bores 60' positioned in the top plate of GIadjacent each of the front legs I2 and I 3 and also adjacent the rearlegs I0 and II. The cut-out portions of the bottom plate 62 are coveredby manner shown most clearly in Fig. 7. At each of the box girdersadjacent, each pf the legs I0,

II, I2, and I3 is a semi-circular channel member I3 welded to'the boxgirders and connected to the legs I0, II, I2, and I3, respectively,.by agusset I311. Circular guide channels I4 are connected (by welding) byspacers I to the channels I3 to provide a space between the channels I4and I3 for purposes to be describedhereinbelow.

The front legs of the upper telescoping section, shown at I1, are guidedin the channel member I4 mounted adjacent the front legs I2, and theback legs I8 of the-telescoping inner section are mounted and guided inguide channels I4 mounted adjacent the rear legs I0 and II. The

inner section is thus securely guided in the lower section and maybe.extended and in its extension is guided by the channels I4.

In a derrick adapted for the use of the derrick latch of my invention Iprefer that at least one of the rear legs, either It] or II, be hollow.Of course, all may be tubular in character but at least one is provided(see Fig. 3 at its lower end close to the bottom channel 9f with a plugor diaphragm I Swhich seals that end of the, tubular member. Adjacentthe diaphragm I9 is provided a drain outlet suitably provided with avalve. The upper end of the tubular leg ad acent the member 9a is alsoclosed by a plug or diaphragm 22, thus providing a sealed tubularconduit between I9 and 22. An inlet line 2I is connected to the tubularmember at some convenient point intermediatethe diaphragm22 and I 9 tobe connected to a source of high pressure fluid such as oil or air forpurposes to be described hereinafter. Mounted underneath the box girder9a is a valve 24 preferably of the rotary type and 2.0- 4

tuated by spokes 25 (see Figs. 2 and 2a) which act to rotate thefour-way plug 24. These spokes are operated by a hingedly mounted dog25' which is mounted on a bracket 26 on one of the legs I8. This dogwill break at the hinge point on the descent of the leg as it contactsthe spokes 25 of the valve so as not to rotate the .valve, but is rigidon the, upstroke of the leg so that it will rotate the valve. In thisfashion the valve is rotated a quarter turn when the upper section 8 israised sumciently so that the dog 25' passes the valve on the upwardmovement of 8, but will not actuate the valve when, on the downwardmovementof section 8, the ,dog again passes by the valve. Y

One of the ports 59 of the four-way plug valve 24 (see Figs. 3 and 6) isconnected by a conduit 28 to the pressure outlet 23 of the tubular legI0,

plates 30 which may be bolted to the bottom plate 62', as shown in'Figs. 4, '5, and 6. These plates carry sleeves 38 welded'to the plates30 on brackets 39.

The sleeves 38 carry bushings 40 in which is rotatably mounted the shaft4|. Mounted on shaft 4| is a collar 42 secured to the shaft M by a keyM. A spring 43 is mounted on shaft 4I between the collar 42 and cap 43'.Hingedly mounted upon the plate 30 at 30a are power cylinders 30'carrying a piston 33 connected to a piston rod 34 which is pivotallyconnected at 35 to a bracket 36adjustably mounted upon a reciprocatingrod 31. at the end of the rod 3! nearest therear legs Ill and I I,respectively, by an arm 46 which is] pivotally connected at to thebracket 44 mounted upon the collar 42. 31, nearest the legs I2 and I 3,is connected to a similar bracket 44 by the arm 4! which is piv- Qotally connected to the bracket 44 by a pivot 45 and connected to therod 31 by means of a sleeve 48 adjustably mounted upon rod 31 by meansof the retaining nuts 49 and 50 which are screwed v onto the threadedend of the rod 31.

The lower end of the shaft II which protrudes beneath the plate 30 isconnected by an arm 5| mounted at right angles to the axis of the shaftM. The arm 5| is connected to a cup 52 whose axis is parallel to theaxis of 4I. The inner diameter of the cup 52 is of such size as toreceive the legs I1 and I8, as will be described below. The cup isbeveled at its upper end at 53 and is closed by a split ring 54 whichextends to form a ledge 55 and has a lip 51 to form a ledge 58.

The operation of the device will be clear from what has been saidbefore. When the derrick is in position on the truck the upper section 8is retracted completely inside the lower section 1. The bottom of theupper section is adjacent the lower girder 9]. When it is desired toerect the derrick, the hydraulic jack 5 is extended, the derrickrotating round the hinge point 3 upon the frame 4 and aroundthe hingepoint 6 on the jack 5, and the derrick is moved into erect positionshown inFig. 1. The bottom derrick section may be latched in position byconventional means usually employed in this art. The

upper section 8 may then be extended by moving this section in itsguideways I4 into the erect:

position shownvin, Fig. 1. Means for extending the derrick are wellknown and are now used in such derricks, or I may use the extendingmeans The rod 31 is connected,

The end of the rod shown in my co-pending. application Ser. No- 10,412.At this point, as well as when the derrick is retracted, the latchingmechanism has the position shown underneath the plates 30 and extendedas shown in Fig. 4-.

As the derrick section 8 moves up, when one of the legs l8 carrying thebracket 26 has reached a point near its upper limit of travel, the dog25 (see Fig. 2) will rotate the valve 24 to place it in position, shownin Fig. 6 The derrick may then move upward a short distance, the dog 25'clearing the arm 25. Pressure is thus applied via leg l and line 28, 60,line 29 to lines 32 and 32. The lines 3| and 3| are vented via line 21,port 6|, bore 24a, port 62, and line 63. The piston rod 34'- is moved inthe direction of the arrow, Fig. 6, to rotate the shaft 4| to move thecups 52 in the direction of the arcuate arrows on Fig. cups from theposition Fig. 4 to the position shown in Figs. 6 and 7. Thederrick legs[8 and the piston is fully I! have been raised so that their lower andis' spaced from the top of the lower section H for a distance greater i.e., the distance between 53 and the bottom 58' of the ring 54. Thispermits the cups to swing into position with the outer rims of the ring54 against [3. This aligns the cups axially with the legs IT and I8,respectively. The upper section is then lowered. The dog 25" breaks atthe hinge point as the arm 26 passes the valve and thus the valve is notactuated. The pressure in the cylinder thus holds the cups against theguide I3. The fourv legs I! and [8 enter the corresponding cups and theweight of the derrick.

pushes the shaft 4| down, the shaft and key M sliding in the. collar 42and the keyway out therein, compressing the spring 43. The cups are seton top of the guide H with the. rim 58 nesting between l3 and I4. Thederrick is thus locked in extended position. Each of the four cups actsimilarly.

Usually the derrick legs l8 are smaller in diameter than the derricklegs I! and the cooperating cups must therefore be dimensioned toreceive these derrick legs. In this position it will be observed thatthe legs rest directly on top of the guide section M which are in turnconnected through the box girders to the legs I0, I l, and [2 of thelower derrick section so that the load im posed on the upper section istransmitted directly to the derrick legs and through the guide sections.It will be observed that none of this load is imposed upon the latchingmechanism except in that the loads are transferred through the ringmembers '54 to the derrick legs. It will also be observed that thegreater the load on 8, the more firmly do the legs seat in the cups andthe more firmly are they latched in position.

In retracting the derrick, the reverse procedure is employed. Thederrick is lifted until the bottom of the legs clears the top rim 53sufficient to permit the spring 43 to retract the rim 58' from betweenI3 and M. In so doing the dog 25 again rotates the valve 90 (see Fig. 2)moving the valve from the position shown in Fig. 6 to that in Fig. 9.The air pressure is now applied to the cylinders through lines 3! and3|, 32 and 32' being vented through 63. This causes the piston andpiston rod to move to the right (Fig. 6') in the direction opposite tothat indicated by the arrow. The cups are swung into the position shownin Fig. by movement in a direction opposite to that of the arrows inFig. 4. The legs may now in Figs. 4 and 5, with the cups through port59, bore 241), port 4. This moves the than the height of the cups,

' tration,

descend along the guideways'. M to permit the.

retraction of the upper derrick section.

While I have described a particular embodiment of my invention for thepurpose of illusit should be understood that" various modifications andadaptations thereof may be made within the spirit of the invention assetforth in the appended claims.

I claim:

1. An automatic latching mechanism for sectional extensible-drillingmasts comprising a lower section, an upper'extensible sectiontelescopically mounted in. said lower section in extensible andretractible position, a latching means mounted on said sections forlatching said upper and lower sections with the upper section inextended position, power actuated means for moving said latching meansinto operative latching position and for moving said latching means intoinoperative unlatched position, automatic means mounted on said mast,said automatic means including means for controlling application. of.power in one direction to actuate said latching means, for moving saidlatching means into operative latching position, and means saidcontrolling means upon the.

for operatingv arrival of said telescoping section at a predeterminedposition during the upward extension of said derrick, said controllingmeans being also. operative to control said power means to move saidlatching means to inoperative unlatching position upon movement of saidupper section from its extended and latched position.

2. An automatic latching. mechanism for sec.

tionel extensible drilling masts comprising a lower section, an upperextensible section telescopically mounted on said lower sectionin'extensible and retractible position, a latching means mounted on.said sections for latchingsaid upper and lower sections with the uppersection in extended position, means for moving said latching means intooperative latching position and for moving said latching means intoinoperative unlatching position, said latching means comprising aninterlock between said extensible members, a pneumatically actuatedpower means mounted on said mast for moving said interlock to operativelatching position and also operative for moving said interlock intoinoperative unlatched position, a pneumatic line connected to said powermeans, a valve in said line mounted on said mast, means mounted on saidmast to actuate said valve to apply the pneumatic pressure in said powermeans to move said latching means from an unlatched to latching positionupon the arrival of said telescoping section at a predetermined positionduring the upward extension of said telescoping section, said valveactuating means being operative also to apply pneumatic pressure in saidpower means to move said latching means to inoperative unlatchingposition for retraction of said derrick from its initial extendedlatched position.

3. A latching means for extensible sectional drilling masts comprising alower section, an upper extensible section telescopically mounted insaid lower section, said sections being composed of cross-bracedlongitudinal members, a latching mechanism for said mast comprising aplurality of cup-shaped members, said members being hingedly mounted onthe cross braces of one of said members, and means for moving saidcup-shaped members about said hinge point into position between thelongitudinal members of the upper and lower sections in loadtransmitting the direction of relationship between the longitudinalmembers of said section.

4. A latching means for extensible drilling masts comprising a lowersection,- an upper extensible section telescopically mounted in .saidlower section, each of said sections composed of longitudinal legmembers, lateral cross bracing between said leg members, a latchingmeans mounted on said lower section, said latching means comprising anarm hingedly mounted on a hinge point positioned on one of the crossbraces on the lower section, a leg receiving member mounted on said arm,means for moving said arm about the hinge point to swing said arm intolatching position underneath the lower end of one of the leg members ofthe upper section upon arrival of said end at a point above said legreceiving member, means mounted upon said lower section underneath saidleg receiving member to engage said leg receiving member in latchingposition, and means for engaging in latching position said lower end ofsaid leg of said'upper section, said leg receiving member and saidaforesaid means in said lower member upon lowering of said leg into saidleg receiving member.

5. A latching means for extensible drilling masts comprising a lowersection, an upper extensible section telescopically mounted in saidlower section, each of said sections composed of longitudinal legmembers, lateral cross bracing between said leg members, a latchingmeans mounted on said lower section, said latching means comprising anarm hingedly mounted on a hinge point positioned on one of the crossbraces on the lower section, a cup mounted on said arm, a pneumaticpower cylinder containing a piston and a piston rod mounted on saidcross bracing upon which said hinge point is mounted, a link betweensaid piston rod and said arm, a pneumatic pressure line connected tosaid power cylinder, a valve in said line and mounted on one of saidsections, a valve actuating means mounted on the; other'section'andacting toactuate said valve upon the'arrival of said upper section at apredetermined location on extension thereof, said hinged arm being oflength suificient to move said cup underneath the end of a leg of saidupper section upon arrival of said upper section at'said predeterminedlocation during the, extension thereof, a cup receiving means mountedupon said lower section underneath said cup when positioned to receivethe endof the leg of the upper'section, and means for engaging inlatching position said lower end of said leg, said cup and saidcupreceiving means upon lowering of-said leg into said cup.

6. An automatic latching'mechanism for Seetional drilling-masts,comprising a lower section,

an upper extensible section, telescopically mount-s ed in said lowersection in extensible and retractible position, a latch means mounted onone, of

; said sections'for latching said upper section in extended positionagainst retractive movement of said extensible section, means mounted onsaid mastfor actuating said latching means to move said latching meansinto a latched position to prevent the retraction of said extensiblesection,

actuating means for moving said latching means into an unlatchedposition to permit the retraction of said extensible section, saidactuating means being "actuable by the arrival of said extensiblesection at a predetermined position during said extension of saidextensible section to cause the latching means to move to latchingposition, and said actuating means including means actuable uponwithdrawal of said extensible section from said position to causethemovement of, said latch from latching position to permit thefurtherretractive movement of said extensible section. V

No reference cited.

JAMES MooN.

